1. Field of the Invention
The invention relates to meat-cutting devices and particularly to a power-driven meat-cutting tool adapted to be manually held and manipulated for the quick and easy removal of meat from carcasses and bones. More particularly, the invention relates to a blade holder for rotatably mounting the blade on the handle and to a method of making the holder from a plastic injection-molded steel ring assembly.
2. Description of the Prior Art
Various styles of power-driven meat-cutting tools have been devised wherein a ring blade is rotatably mounted within a holder which, in turn, is mounted on a manually operated power-driven handle. These tools have been used for some time to facilitate the removal of meat from a carcass, primarily in a trimming operation, or for removing the meat remains from the animal bones. Examples of such meat-cutting tools are shown in U.S. Pat. Nos. 3,024,532, 3,176,397, 3,269,010, 3,461,557 and 3,852,882.
One of the preferred types of such meat-cutting tools is the type shown in U.S. Pat. No. 3,269,010. This tool consists of an annular metal ring having an internal blade mounting groove formed therein, with a pair of metal scalloped lugs being formed on opposite sides of a split in the ring and formed integrally with the metal of the ring. A gear-receiving chamber is formed in the scalloped lugs in addition to mounting holes for attaching the blade holder to an end of a power-driven handle.
These types of blade holders are formed entirely of metal and require a considerable number of machining and metal working operations to form the final configuration from a piece of tubular metal stock. FIG. 1 of the accompanying drawings illustrates an example of one of these prior art blade holders.
These holders require a considerable number of manufacturing steps and various types of metal working equipment. Initially, the tubular starting blank is placed in a turret lathe and an internal annular groove is formed in the blank in a relatively simple operation. Likewise, the outside diameter of the metal blade housing is turned in the blank while the blank is in this lathe. Next, the partially formed blade housing is cut off from its original tubular bar stock, having a predetermined axial length. Next, this removed tubular section is mounted in a milling machine wherein a circular recess is cut radially into a portion of the cylindrical wall to provide a gear chamber.
After formation of this gear chamber, the part is put into another turret lathe and an external annular alignment groove is formed in the outer surface of the blank for subsequent engagement with keys mounted on the power-driven handle. After this alignment groove is formed, two mounting holes are drilled radially through the cylindrical wall, one on each side of the gear chamber. The housing ring next is placed on a slotter which forms a relatively precise cut almost completely through the cylindrical wall and remaining metal portion which forms the back of the gear chamber, without completely separating the ring. At this stage, the part is still in a uniform axial cylindrical configuration, in that no scalloped mounting lugs or formation has been formed thereon.
The part then is sent through a heat treatment stage, after which it is placed in a grinder. The grinder removes a considerable amount of the stock away from the partially machined and heat-treated part, ending up with the particular ring-like configuration shown in FIG. 1, with a scalloped rear mounting portion. This grinding requires some degree of accuracy to form the scalloped mounting portion and remaining ring-like portion. This grinding step is generally the singular most expensive operation performed on the part and the most difficult to control due to the non-uniform shape finally resulting therefrom. This is especially difficult since the grinding has to be done after the heat treatment step. Also, the ring portion should be ground to as small an axial length as possible so that the blade can sufficiently remove meat from between bones and in as many narrow areas of the carcass as possible to get the most meat from the carcass. This is important both to the operator and ultimately to the customer.
This grinding procedure must be done after the heat treatment due to the non-uniform configuration of the final blade housing, which, if heat treated in this final non-uniform shape, would develop internal stresses which could distort the part sufficiently whereby the blade mounting groove would be out of roundness, preventing smooth running of the rotating blade therein.
After the grinding operation is complete, the remainder of the partially formed slot in the scalloped area and gear chamber then is ground completely through, permitting the ring to be separated and flexed for the subsequent mounting of a blade therein. Next, the split ring is either shot-peened with glass beads or other granular material or placed in a hopper in order to clean the ring and to remove sharp corners, edges and burrs therefrom. Some hand grinding also may be required to remove the sharp corners and burrs resulting from the extensive machining and grinding operations.
It is easily seen that the above-described operations and procedures, many of which may be done manually, increase considerably the cost of the final blade holder.
No blade holder construction of which I am aware has eliminated many of these costly metal working procedures by injection molding a pair of mounting lugs directly on a metal insert ring which has been preformed with the blade mounting groove therein.